Exhaust manifold for four-cycle internal-combustion engines



July 8, 1947.

C. G. BARRETT EXHAUST MANIFOLD FOR FOUR-CYCLE INTERNAL-COMBUSTION ENGINES Filed May 19, 1945 2 Sheets-Sheet l L n 1 No am wm n1 mT; S x 5 S 2. s 3 Q 5 8. 3 5 Q. an 93 n we we 5. 5 we 5 mm mm mm on m an July 8, 1947. c, BARRETT 2,423,574

EXHAUST MANIFOLD FOR FOUR-CYCLE INTERNAb-COMBUSTION ENGINES Filed May 19, 1945 2 Sheets-Sheet 2 Charles 6.3arreflattorneys haust blasts to the other passage.

UNITED STATES PATENT OFFICE EXHAUST MANIFOLD FOR FOUR-CYCLE INTERNAL-COMBUSTION ENGINES Application May 19, 1945, Serial No. 594,734

3 Claims.

ng an engine it is highly desirable .mneetions for the exhaust of the re it has been proposed to provide ct manifold passages, and to connect to e such passage cylinders whose exhaust do not materially overlap. In foure engine, three cylinders can be connected one passage without serious overlapping or i terference provided their cranks are spaced at uniform intervals (i. e. 120 oi crank angle).

six-cylinder engine would thus require two L exhaust passages, and a convenient ar nent according to the invention is to have two passages, one of which serves cylinders 1, 2 and 3, and the other of which serves cylinders i, and 6. The firing order must be such that exhaust blasts to one passage alternate with ex- As a practical matter the firing order 1, 5, 3, 6, 2, 4 is the only one which will meeet this requirement and still afford the best running balance. For this order the cranks shoe in pairs, as follows: 1 and 6; 2 and 5; 3 and 4.

The invention is intended for large engines, particularly compression ignition engines, and may or may not deliver the exhaust gases to a turbo-charger. It affords a comparatively light manifold which may be fabricated from plate and pipe by welding, which may be water cooled, which has a slender cylindrical configuration, and in which the two exhaust passages are so .ated that the minimum avoidable re offered to exhaust flow.

. an. i in perhaps oven-simplified terms, a cyl ndrical manifold shell is divided into two by diametric plate which is twisted between the connections to cylinders 3 and 4, so cylinders l, 2 and 3 enter at one side of the te and cylinders 4, 5 and 6 enter at the other The necessary amount of twist is a function of the diameters of the cylinder connections and. the diameter of the manifold shell, but orly is about 120, and commonly is less rather With conventional cylinder spacing, rds a'gradual twist. Except in the twiste between exhaust flows from differ 2 ed portion between the cylinders 3 and 4 the diametric plate is straight and extends from end to end of the manifold shell.

A preferred embodiment of the invention will now be described by reference to the accompanying drawings, in which:

Fig.1 is a plan view of the complete manifold, with a terminal connection for a turbo-charger.

Fig. 2 is a section on the line 2-2 of Fig. 1. The cooling core and the divider plate are shown in elevation.

3 is fragmentary horizontal axial section on a larger scale than Fig. 1.

c re transverse sections on a still planes of section being indili. 5-WE Oi). l.

elevation of the right-hand, end of cated at Fig. .6 the manifold.

Fig. 7 is a section on the line 11 of Fig. 6.

Fig. 8 is a perspective of the diametric divider plate showing the helical twist. Parts of the straight end portions are broken away to reduce the length of the view.

Fig. 9 is a fragmentary axial section on the same plane as Fig. 2, but drawn to a larger scale.

All statements or direction relate to the parts simply as they are shown in the drawings.

The manifold comprises two cylindrical shells, an outer jacket shell I l and a coaxial inner shell 12 which is the manifold proper. The two are held in coaxial relation by a. central pipe or water-core l3.

At the left-hand end (see Fig. 9) an annular head It connects the outer shell II and the water-core l3, and an annular head l5, spaced inward from head l4 connects the inner shell (see Fig. 7) an oiitake fitting l5 having two exhaust connections I1 and I8 is connected to the outer shell ll, inner shell I! and water-core I3. The last-named connection is through a part IQ of the divider plate, and a head 2| which closes the right-hand end of the water-core l3. All the joints mentioned above are welded.

The part I9 is the bridge part of a U-shaped fiat plate 22 which straddles the right-hand end of the water-core l3 and divides the annular space between the parts 42 and I3 into two distinct passages which lead respectively to the connections l1 and I8. The two arms of plate 22 are continued, each by a helical plate 33 located at mid-iength of the manifold and a straight flat plate 24 at the left-hand end of the manifold. The plate 22 is welded to plates 23 where their ends meet (see 25, Figs. 2 and 8), and the latter to plates 24 where their ends meet (see 26, Figs. 2 and 8).

The plates 22, 23 and 24 are preferably welded continuously to the water-core l3 and shell l4 throughout their respective contacts, so that the two passages in the manifold are completely separated. An arcuate divider 2! (see Figs. 2, 3 and 7) is welded to parts I3, 23 and I2 to close one passage within the manifold. The left-end of Water-core I3 is closed by cap 28. An inlet pipe 29 delivers cooling water to the far (right-hand) end and an off-take connection 3| assures return flow through the entire length of the core. Spacers 32 (see Fig. 3) help to hold core l3 centered.

Though the method of assembling and Welding is not a part of the claimed subject matter of this application, it seems expedient to mention the preferred procedure. The water-core I3 is made up and the parts 23 are welded to it. Then a tube approximately coextensive in length with parts 23 and destined to form the middle part of shell I2 is slid over the helical parts 23 and welded thereto. Then the parts 22 and 24 are placed and welded to core l3 and to parts 23. The parts 22 and 24 are wider in a radial direction than.

are the parts 23, so the two end sections of the shell l2 are applied as the halves of a longitudinally split tube (see the welds 33 and 34 in Figs. 4 and It follows that the cylindrical portion of shell I2 is actually made of five pieces welded into a unitary whole.

Three cylinder exhaust connections 31 are connected to openings in shell l2 to the left of the helical plates 23 and three cylinder connections 38 are located to the right of the helical plates 23. The six connections 37, 38 are identical andare uniformly spaced. Each has a connecting flange 39 and each is enclosed by a bonnet 4| which is Wel ed to it and to the margin of a corresponding opening in outer shell I l The three connections 31 (assumed to be from cylinders 1, 2 and 3) lead to one passage in shell l2 and thence to connection l1, being deflected about 120 at the helical offset 23. The three connections 38 (assumed to be for cylinders 4, 5 and 6) enter the other passage which leads straight to connection l8. The left-end of this second passage is closed by plate 22', so that a portion of the second passage is unused. It is, however, considered simpler and better to have a complete cylindrical manifold, than to omit the unused left-end portion of this passage.

Pyrometer connections are shown at 42. Water connections for the jacket space between shells H and 12 are shown at 43, while vent and drain connections are shown at 44 and 45 respectively.

since there is only negligible overlap of exhaust periods fo either passage. The flow from cylinders l to 3 will be only slightly diverted, and the inclined arrangements of connections 37, 3B favors sustained flow.

Consequently the invention afiords excellent simple exhaust flow characteristics in a light structure having a very simple and neat cylindrical contour.

What is claimed is:

1. An exhaust manifold for a four-cycle internal combustion engine having six cylinders arranged in line and a firing order such that cylinders in the respective longitudinal halves of the row of six. cylinders xhaust alternately, said manifold comprising an elongated generally cylindrical shell having lateral exhaust connections leading thereto; a partition extending from end to end of the manifold and substantially diametrically across the same to subdivide the manifold into two distinct longitudinal passages, said partition being helically displaced between the connections from the third and fourth cylinders sufficiently to cause the first, second and third exhaust connections to enter one passage and the fourth, fifth and sixth to enter the other, and means for closing the latter of said passages at a point between the connections leading from the third and fourth cylinders.

2. An exhaust manifold for a four-cycle internal combustion engine having six cylinders arranged in line and a firing order such that cylinders in the respective longitudinal halves of the row of six cylinders exhaust alternately, said manifold comprising an elongated generally cylindrical shell having lateral exhaust connections leading thereto; and a partition extending from end to end of the manifold and substantially diametrically across the same to subdivide the mani-;.- fold into two distinct longitudinal passages, said partition being straight except between the connections from the third and fourth cylinders, and being there helically displaced sufficiently to cause the first, second and third exhaust connections to enter one of said passages and the fourth, fifth and sixth to enter the other.

3. An exhaust manifold for a four cycle internal combustion engine having six cylinders arranged in line and a firing order such that cylinders in the respective longitudinal halves of the row of six cylinders exhaust alternately, said manifold comprising an elongated generall cylindrical double walled shell having lateral exhaust connections for respective cylinders leading to the interior of the inner wall of the shell; .a tube extending axially through the shell; din metrically arranged webs spanning the intervals between said tube and the inner wall of said shell connected to both and serving to divide the said interval into two distinct longitudinal passages, said webs being straight except between the con nections for the third and fourth cylinders and there being deflected to cause the first, second and third exhaust connections to enter one of said passages and the fourth, fifth and sixth to enter the other; and water circulating connections for leading water to and from the space between the walls of said shell and to and from said tube.

CHARLES G. BARRETT.

REFERENCES CITED The following references are oi record in the file of this patent:

UNITED STA'IEEB PATENTS Noll 

